Classification of GA response,Rht genes and culm length in Japanese varieties and landraces of wheat

Summary The GA response, Rht genes and culm length of 133 Norin varieties, 6 breeding lines and 16 landraces of Japanese wheat were investigated. Out of 133 Norin varieties tested, 103 were GA-insensitive and 30 GA-responsive. The 6 breeding lines were all GA-insensitive. Out of 16 landraces tested, 10 were GA-insensitive and 6 GA-responsive. Among the 10 GA-insensitive landraces, only Daruma had a Rht1 genotype. The other 9 had a Rht2 genotype. None of the landraces tested carried both Rht1 and Rht2 or Rht3. Out of the 103 GA-insensitive Norin varieties, 22 carried only Rht1, another 79 carried only Rht2, and only Norin 10 and Kokeshikomugi carried both Rht1 and Rht2. No tested variety carried Rht3. Some Norin varieties carrying Rht2 showed tall culms comparable to that of the rht tester line Chinese Spring. These results suggest that these varieties had a nullifier or modifier gene(s) or height promoting genes in the background controlling the height-reducing effect of Rht2. Conversely, six GA-responsive Norin varieties were as short as Akakomugi which carries the GA-responsive Rht genes, Rht8 and Rht9. The also seemed to carry a GA-responsive Rht gene or genes, and moreover all but one may carry gene(s) other than the Akakomugi genes. The origin of Rht1 and Rht2 of Norin 10 was speculated on the GA-response and Rht genotypes of its related varieties and landraces.     

Dwarfing effect associated with the threshability gene Q on wheat chromosome 5A

A dwarfing effect of the 44.1 cM chromosomal region between the threshability gene Q and Xfba068 on the long arm of hexaploid wheat chromosome 5A has been reported. To clarify whether Q or its adjacent region is responsible for regulating culm elongation, two precise genetic stocks of near‐isogenic lines (NIL), a single chromosome substitution line, ‘Chinese Spring’ (CS; ‘Cappelle‐Desprez’ 5A) (NIL‐Q) and a single chromosome recombinant substitution line (NIL‐q) were used. The target segment of NIL‐q included the q allele and QEet.ocs‐5A.1, an earlinessper se gene, from spelt wheat in the CS genetic background. They were grown under 16‐h day length with and/ or without vernalization treatment. Being independent of heading date, NIL‐Q showed shorter elongation in lower internodes and decreased internode differentiation in comparison with NIL‐q. The culm‐length reduction associated with Q was confirmed in the recombinant F5 population derived from the cross between NIL‐Q and NIL‐q. Vernalization promotion had a tendency to reduce this dwarfing effect.     

沼气发酵液防治水稻白叶枯病和纹枯病的研究

沼气发酵液对于水稻白叶枯病和纹枯病有明显的防治效果。使用沼气发酵液比使用化肥和猪杂肥,水稻白叶枯病的病叶率降低11.29～21.43％、病情指数降低11.86～25.47％,预防效果为48.32～43.42％,治疗作用为17.61～17.92％;水稻纹枯病的病叶率降低9.83～26.16％,病情指数降低了44.94～66.52％;千粒重增加3.08～7.80％,理论产量较单施化肥增加22.22～28.41％。     

杂交稻再生芽发育与母秆性状的相关性研究

对杂交中稻优-63再生芽生长发育与母秆性状的相关性研究表明,株高、叶面积与倒2、3、4节的活芽长在孕穗期至齐穗后28天均呈极显著正相关;与倒5节活芽长在部分时期呈显著或极显著正相关.株高或叶面积均可作为预测倒2～4节活芽长的形态指标.各节节径与活芽长除齐穗期和完熟期外,均呈显著正相关.全氮、全糖、淀粉、活芽长与芽穗分化呈一定正相关,而以活芽长最为显著.节重、节径与芽穗分化无显著相关.生育进程与芽穗分化呈极显著正相关.下位芽分化迟、后期分化快。上位芽分化早、前期分化快.     

厚皮毛竹厚壁性状的表型遗传分析

厚皮毛竹原产地和引种地表型遗传变异稳定。分析了其生物量／胸围系数、竹壁厚度、秆壁率和地上部生物量分配,初探了厚皮毛竹起源。     

浙江省竹质人造板生产现状

浙江现有竹质人造板厂18家,其中集体、乡镇企业15家,个体联营3家,4家系1988年新建。主要产品有竹席胶合板、竹篾层压板、竹篾胶压板、竹编胶合建筑模板、竹编贴面装饰板和竹旋片装饰板等。年产竹席胶合板109.6万m~2,竹篾胶合板0.19万m~3,竹编胶合建筑模板12.5万m~2。1987年产值980万元,利润80万元;1988年产值1394万元,利润122.7万元。当前浙江省竹质人造板行业主要存在产品缺乏必要检验,产品质量不稳定,竹材、胶粘剂等生产资料提价过高,企业经济效益低,企业管理水平较差,原竹利用率低等问题。     

寒地水稻品种成熟期茎鞘干重变化过程及其对结实率的影响

选用黑龙江省目前生产上典型高产水稻品种或新育成的超高产有望品系 11个 ,在超高产栽培条件下研究寒地水稻品种成熟期茎鞘干重变化过程的差异及其和结实率的关系。结果表明 ,(1)水稻成熟期茎鞘干重变化过程可分为 3个阶段 ,阶段 茎鞘干重升高 ,阶段 持续降低 ,阶段 趋于稳定 ;(2 )不同品种成熟期茎鞘干重变化过程不同。依据阶段 有无将供试品种分为两类 ,A类型具有阶段 、 和 ,B类型只有阶段 和 。A类型品种结实率较高。 (3)不同品种阶段 持续时间长短有差异 ,有的品种 5 d,有的品种 10 d,时间短的品种结实率较高。 (4)不同品种茎鞘阶段 的茎鞘干重降低速率不同。此阶段单位颖花每天从茎鞘获得物质的最大量高 ,有利于提高结实率     

小麦叶鞘枯萎病发生规律及防治技术研究

研究小麦叶鞘枯萎病的田间发生规律,探讨了发病程度和危害损失与环境因子的同时进行人工综合防治技术的研究。研究结果,该病在小麦拔节至孕穗期始发,抽穗期病期快速发展,扬花灌浆期达发病高峰,乳熟后病情基本稳定,该病改天吉温低温病害,其田间发病程度和危害同土壤类型、小麦拔节孕穗期的气温、雨日、雨量、以及施肥水平关系密切;综合防治中应坚持人工调控麦田生态环境为中心,开展健身栽培,在病害始发期和快速扩展期用化学     

水稻茎秆特性与抗倒伏关系的研究现状

倒伏是水稻(Oryza sativa L.)生产上面临的一大难题,随着近年来超级杂交稻的推广,水稻株高已由矮秆、半矮秆向半高秆发展,株高的增加加大了水稻植株倒伏的可能性。水稻倒伏与其茎秆的关系密切,主要与水稻节间性状、节间维管束及茎秆化学成分有关。对水稻茎秆特性与其抗倒伏能力的关系进行了综述。     

种植方式对杂交籼稻植株抗倒伏特性的影响

为探讨机械化播栽方式对杂交籼稻植株抗倒伏能力的影响,以F优498为材料,在大田进行了以种植方式为主区、穴苗数为副区的裂区试验,种植方式包括机直播、机插和手插3种,穴苗数分低苗和高苗2个处理。在齐穗后30 d,调查植株茎鞘物理性状、力学和抗倒伏特性,并分析茎鞘性状与抗倒伏特性的相关性。结果表明: (1)不同种植方式之间水稻倒伏指数差异极显著,手插稻最低,机插稻最高,机直播稻介于二者之间。这种差异主要与节间折断弯矩有关,N₁–N₄节间折断弯矩与节间粗度和厚度、秆型指数、比茎重、节间干重、断面模数和弯曲应力都呈显著或极显著正相关,与节间长度呈显著或极显著负相关;基部节间的植株折断弯矩变异较小,且低位节间的弯曲力矩显著高于高位节间,这是水稻植株基部第1、第2节间易倒伏的主要原因。(2)手插稻基部节间短,茎粗壁厚,秆型指数、茎鞘充实度和弯曲应力高,最终表现为植株折断弯矩和抗倒伏能力强;机插稻群体大,个体生长受抑制,倒伏指数大。为构建合理的群体结构,以机械化播栽稻每穴3~4苗、手插稻每穴2苗,有利于相对实现高产与抗倒的协调。